JP3502970B2 - Liquid filled type vibration damping device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled type vibration damping device capable of obtaining a vibration damping effect based on the flow of a fluid (liquid) sealed inside, and in particular,
A liquid-filled type vibration damping device in which vibration damping characteristics exhibited with the flow of liquid can be switched to multiple stages by a vibrator having a simple structure driven by engine suction negative pressure Is.

[0002]

2. Description of the Related Art Among vibration isolation devices, particularly in engine mounts for automobiles, an engine, which is a power source, is operated under various conditions from idling to the maximum rotation speed. Since it is used, it must be able to handle a wide range of frequencies. In addition, recently, engine mounts have been tuned for the purpose of blocking muffled noise caused by vibration in a relatively high frequency range. In order to meet such a plurality of conditions, a so-called voice coil type in which a liquid chamber is provided inside, and further a vibrator including a voice coil that vibrates at a specific frequency is provided inside the liquid chamber The liquid-filled type vibration damping device has already been devised and is known, for example, from Japanese Patent Application Laid-Open No. 5-149369. However, these known ones are provided with a plurality of liquid chambers, a movable piece including a piston or the like is provided in the liquid chamber, and a voice coil for driving the movable piece is further provided. Its structure is complicated. Therefore, these known devices have a problem in that they have to be heavy as a whole as a vibration isolator because they have many parts such as an exciting coil and a permanent magnet. In order to solve such a problem, an oscillating device having a simple mechanism driven by the suction negative pressure of the engine is provided, so that various vibrations including idling vibration can be cut off. Things have already been developed, for example, as shown in FIG.

[0003]

By the way, in the above-mentioned conventional one, the vibration isolation mechanism portion 10 is provided in the main chamber 110 which is continuously provided with the insulator 20, and the diaphragm 15 is provided in the main chamber 110.
It is designed to be formed on the basis of the equilibrium chamber 130 provided through 0. Then, the engine suction negative pressure or the atmospheric pressure is introduced into the equilibrium chamber 130 by the switching means 30 which performs a switching operation based on the control action of the control means 50. In particular, when shutting off vibration during engine idling, the switching valve 310 forming the switching means 30 is opened / closed in accordance with the frequency during engine idling, whereby the engine suction negative pressure and the atmospheric pressure are reduced. The equilibrium chamber 130 is alternately introduced. By the way, in introducing the negative pressure and the atmospheric pressure, when the switching valve 310 is opened and closed at a predetermined cycle (frequency) as shown in FIG. 4, the pressure in the equilibrium chamber 130 at that time is changed. The fluctuation, that is, the fluctuation state of the exciting force has an asymmetrical waveform as shown in FIG. By exhibiting such an asymmetrical waveform, noise of a high frequency component or the like is emitted, which causes a complicated high frequency vibration sound to propagate into the vehicle interior instead of idling vibration. In order to solve such a problem, it is an object of the present invention to provide a liquid-filled type vibration damping device in which the pressure fluctuation in the equilibrium chamber exhibits a symmetrical waveform of a sine wave when negative pressure is introduced and atmospheric pressure is introduced. That is the object (problem) of the present invention.

[0004]

In order to solve the above-mentioned problems, the following measures are taken in the present invention. That is, in the first aspect of the invention, the upper connecting member attached to the vibrating body, the lower connecting member attached to the member on the vehicle body side, and the vibrating body located between the upper connecting member and the lower connecting member. And an anti-vibration mechanism section that is provided in series with the insulator and that is formed in a liquid chamber or the like in which a liquid that is an incompressible fluid is sealed. Regarding a liquid-filled type vibration damping device, the vibration damping mechanism is configured such that a chamber wall is formed in a part of an insulator and a liquid is sealed in a main chamber and an orifice is provided in the main chamber. A sub-chamber connected to the main chamber and separated from the main chamber by a partition plate; an air chamber provided below the sub-chamber and provided via a third diaphragm; An equilibrium chamber, which is provided in the chamber through a first diaphragm and is formed so that either one of atmospheric pressure and negative pressure is introduced, the main chamber and the sub chamber. And is formed so that the liquid in the main chamber is introduced via a communication passage having a predetermined volume, and is partitioned and formed via a second diaphragm, and A third liquid chamber formed so that the volume can be changed, and, in the equilibrium chamber having such a configuration, one of negative pressure or atmospheric pressure,
A switching means for performing a switching operation is provided so as to introduce continuously or alternately in a state synchronized with the engine vibration,
Further, a configuration is adopted in which control means for controlling the switching operation of the switching means is provided.

By adopting such a structure, the present invention has the following effects.
That is, with respect to idling vibration, by operating the switching means, negative pressure or atmospheric pressure is alternately introduced with a specific frequency into the equilibrium chamber provided in the lower portion of the main chamber. To do. That is, by operating the switching means at a specific frequency, the pressure (volume) in the equilibrium chamber is changed, and thereby the fluid pressure fluctuation in the main chamber caused by the idling vibration input via the insulator. To absorb. As a result, the dynamic spring constant of the spring system formed by the insulator and the anti-vibration mechanism section is reduced. Particularly, in this case, in the present invention, the liquid in the communication passage connecting between the second diaphragm and the main chamber resonates with the liquid pressure fluctuation of the liquid in the main chamber. It has become. As a result, the change state of the generated force (vibration energy) formed in the entire antivibration mechanism section becomes a sine wave having a symmetrical waveform as shown in FIG. 3, for example. As a result, the idling vibration is accurately absorbed and blocked. Further, it is possible to avoid the occurrence of high-frequency vibrations and the like that occur due to the cutoff of the idling vibrations.

Further, for the engine shake, which is a vibration of a frequency lower than the idling vibration, the liquid is caused to flow in the orifice connecting the main chamber and the sub chamber, whereby Absorb and block engine shake. That is, since the vibration related to the engine shake has a frequency of about 10 Hz, it is difficult to cut off the vibration by lowering the dynamic spring constant. Therefore, in the present invention, a constant negative pressure is continuously introduced into the equilibrium chamber that forms the anti-vibration mechanism section, and the first diaphragm that forms the equilibrium chamber is pulled down to lower the equilibrium chamber. To zero volume. This prevents volume changes in the equilibration chamber.
In such a state, when the vibration from the vibrating body is propagated to the insulator, the lower surface of the insulator vibrates in response to the vibration and positively moves the liquid in the main chamber to the sub chamber side. Operates to flow. As a result, the liquid in the main chamber flows through the orifice toward the sub chamber. A predetermined damping force is generated by viscous resistance accompanying the flow of the liquid, and the engine shake is suppressed (damped) by this damping force.

On the other hand, with respect to vibration of a high frequency of about 100 Hz to 600 Hz, which causes a muffled noise which is a problem while the vehicle is running, the switching means is operated to open the equilibrium chamber to the atmosphere. To As a result, atmospheric pressure is introduced into the equilibrium chamber, and the first diaphragm forming the equilibrium chamber is allowed to freely operate (vibrate). As a result, the liquid in the main chamber flows relatively freely in the main chamber in response to the vibration input from the insulator side. As a result, the dynamic spring constant of the spring system formed by the entire vibration damping device can be suppressed low. Therefore, the effect of blocking vibrations in the high frequency range is enhanced. As described above, in the present invention, a plurality of types of vibrations are absorbed and blocked by the operation of the switching means such as the switching valve.

Next, the invention according to claim 2 will be described. The basic point of this is also the same as that of the above-mentioned claim 1. The feature is that the surface of the second diaphragm provided at the vibration isolation mechanism opposite to the side facing the third liquid chamber is provided with a partition wall having a plurality of openings. This is to face the sub chamber through the above. That is, the vibration isolation mechanism portion continuously provided in the insulator is a main chamber in which a chamber wall is formed in a part of the insulator and a liquid is sealed, and an orifice is provided in the main chamber. A sub-chamber connected to the main chamber and separated from the main chamber by a partition plate, an air chamber provided below the sub-chamber via a third diaphragm, and the main chamber described above. An equilibrium chamber formed to introduce either one of the atmospheric pressure and the negative pressure, which is provided through the first diaphragm in the chamber, and the main chamber and the sub chamber. The liquid is introduced between the main chambers through a communication passage having a predetermined volume, and is partitioned and formed through a second diaphragm, and the volume of the liquid is defined by the second diaphragm. Formed to be changeable And a third liquid chamber that is formed on the side opposite to the side of the second diaphragm facing the third liquid chamber via a partition wall having a plurality of openings. The liquid in the sub chamber is introduced. By adopting such a configuration, the effect of blocking the vibration related to the idling vibration and the muffled sound is exhibited.
Further, in addition to these, the displacement of the second diaphragm can be regulated by the partition wall with respect to the low-frequency vibration input mainly of the engine shake, and the liquid in the main chamber can be controlled. It becomes possible to promote the flow of the above into the sub chamber. As a result, the liquid in the main chamber flows in the orifice, so that high damping characteristics can be obtained.

Next, the invention according to claim 3 will be described. The basic point of this is also the same as that of the above-mentioned claim 1. The characteristic is that the equilibrium chamber is provided with a minute passage (fine passage) on the surface side of the second diaphragm forming the vibration isolation mechanism opposite to the side facing the sub chamber. That is, the air chamber to be connected is provided. That is, the vibration isolation mechanism portion continuously provided in the insulator is a main chamber in which a chamber wall is formed in a part of the insulator and a liquid is sealed, and an orifice is provided in the main chamber. A sub-chamber connected to the main chamber and separated from the main chamber by a partition plate, an air chamber provided below the sub-chamber and provided via a third diaphragm, and Between the main chamber and the partition plate, which is provided via the first diaphragm, between the atmospheric pressure and the negative pressure, the equilibrium chamber formed so that either one is introduced, It is provided between the main chamber and the sub chamber, is formed so that the liquid in the main chamber is introduced through a communication passage having a predetermined volume, and through a second diaphragm. Compartment is formed and its volume changes And a third liquid chamber formed so as to be effective, and a fine passage is provided on the surface of the second diaphragm opposite to the surface facing the third liquid chamber. Then, the configuration is such that an air chamber connected to the equilibrium chamber is provided.

By adopting such a structure, in the present invention, in addition to the structure described in claim 1,
Furthermore, the following effects are exhibited. That is,
When shutting off the engine shake, a constant negative pressure is continuously introduced into the equilibrium chamber, thereby bringing the volume of the equilibrium chamber to zero and connecting the main chamber with the main passage through a communication passage. The second diaphragm may also be made inoperative by adsorbing it to the equilibrium chamber side. As a result, when the vibration caused by the engine shake is propagated to the liquid in the main chamber through the insulator, the liquid in the main chamber is efficiently compressed,
It is sent out to the sub chamber side through the orifice. That is, the liquid in the main chamber flows in the orifice. As a result, high damping characteristics can be obtained by the flow action of this liquid in the orifice. Due to the action of this high damping characteristic, the vibration related to the engine shake is suppressed. With respect to engine idling vibrations other than the engine shake and muffled noises in the high frequency range, the same cutoff effect as that of the above-described claim 1 can be obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. Although it relates to the first embodiment (first embodiment) of the present invention, its configuration is as shown in FIG.
As shown in, the upper connecting member 6 attached to the vibrating body
And a lower connecting member 9 attached to a member or the like on the vehicle body side
An insulator 2 between the upper connecting member 6 and the lower connecting member 9 for absorbing and blocking vibrations from the vibrating body, and an incompressible fluid provided in series with the insulator 2. A vibration isolating mechanism portion 1 including a liquid chamber formed by a main chamber 12 and a sub chamber 16 in which a liquid is sealed, and a part of the vibration isolating mechanism portion 1. In the equilibrium chamber 13 provided inside,
Switching means 3 for performing switching operation so that either one of the negative pressure and the atmospheric pressure is introduced continuously or alternately in a state synchronized with the engine vibration, and the switching operation of the switching means 3. The control means 5 for controlling is basically used.

In such a basic structure, the insulator 2 is made of a rubber-like elastic body such as a vibration-proof rubber material, and one end surface of the insulator 2 is integrated with the upper connecting member 6 by vulcanizing bonding means or the like. It is designed to be combined with each other. The vibration isolating mechanism portion 1 provided in series with such an insulator 2 is provided below the insulator 2 in succession to the insulator 2 and has a main chamber 12 in which a liquid is sealed. When,
A first diaphragm (first diaphragm) 11 is provided in a lower portion of the main chamber 12 through,
The equilibrium chamber 13 into which a negative pressure or an atmospheric pressure is introduced based on the switching operation of the switching means 3 and the main chamber 12 are provided via a partition plate 14, and like the main chamber 12, A sub-chamber 16 in which a liquid is enclosed, an orifice 15 connecting the main chamber 12 and the sub-chamber 16, and a space provided between the main chamber 12 and the sub-chamber 16 and having a predetermined volume Is formed such that the liquid in the main chamber 12 is introduced through the communication passage 121 having the above, and is formed so as to be partitioned through the second diaphragm 122, and the volume thereof can be changed. A third liquid chamber 124,
It is provided below the sub chamber 16 via a third diaphragm (third diaphragm) 17 and basically comprises an air chamber 18 into which air is always introduced.

The second diaphragm (second diaphragm) forming the main vibration-damping mechanism section 1 having such a structure.
The configuration around 122 will be described. That is,
The second diaphragm 122 includes the main chamber 12 and the sub chamber 16
It is provided at a partition plate 14 for partitioning the space between the main chamber 12 and the main chamber 12 through a communication passage 121 having a predetermined volume on one surface side (upper surface side) thereof. A third liquid chamber (third liquid chamber) 124 is formed so that the liquid therein is always introduced. Then, on the other surface side (lower surface side), a rigid partition wall 19 having a plurality of openings 191 is provided with a slight gap therebetween. Further, in the present embodiment, the liquid in the sub chamber 16 is always introduced into the small chamber 126 formed with this slight gap through the opening 191. It is what

Next, a second embodiment (second embodiment) of the structure around the second diaphragm (second diaphragm) 122 having such a structure will be described. Also in this case, the basic points are the same as those described in the first embodiment. The feature is that, for example, in FIG. 1, the rigid partition wall 19 provided on the lower surface side of the second diaphragm 122 in the first embodiment is hermetically sealed at the opening 191 thereof. -Shaped partition wall 19 and the second diaphragm 1
The small chamber 126 formed between the small chamber 126 and the small chamber 22 is an air chamber. By adopting such a configuration, the second diaphragm 122 is provided with the third liquid chamber 12
In accordance with the fluctuation of the hydraulic pressure in the chamber 4, it is possible to freely vibrate within the range of the volume of the small chamber (air chamber) 126. And the small chamber 1 which forms such an air chamber
26 may be of a closed type, or may be of the atmospheric type via another passage or the like.
Further, although the air chamber is provided so as to face the third liquid chamber 124 with the second diaphragm 122 sandwiched therebetween, as a typical example thereof, the structure shown in FIG. There is something like.

This is the second diaphragm 122 described above.
One surface side (upper surface side) is provided with an air chamber 125 connected to the equilibrium chamber 13 through a fine passage 123, and the other surface side (lower surface side) is A third liquid chamber (third liquid chamber) 124 connected to the main chamber 12 via a communication passage 121 having a predetermined volume is provided. Atmospheric pressure is introduced into the air chamber 125 when the equilibrium chamber 13 is open to the atmosphere or when negative pressure and atmospheric pressure are alternately introduced. ,
When the equilibrium chamber 13 is in a continuous negative pressure state, a negative pressure is introduced so that the balance chamber 13 and the equilibrium chamber 13 are brought into a state of zero volume. That is, when the fine passages 123 function as throttles and the atmospheric pressure and the negative pressure are alternately introduced into the equilibrium chamber 13 in a predetermined cycle,
The air chamber 125 does not follow it. Further, the liquid in the main chamber 12 is always introduced into the third liquid chamber 124 side through the communication passage 121. The third liquid chamber 124 is isolated from the sub chamber 16 by a part of the partition plate 14 made of a rigid body. Therefore, when a negative pressure is continuously introduced into the equilibrium chamber 13 and the volumes of the equilibrium chamber 13 and the air chamber 125 are set to zero, the volume fluctuation in the third liquid chamber 124 cannot occur at all. It is something like this.

The switching means 3 which operates so as to introduce the negative pressure or the atmospheric pressure into the equilibrium chamber 13 provided in the main chamber 12 via the first diaphragm 11 in a properly switched state is a three-way valve. And a solenoid 32 for driving the switching valve 31. A throttle valve 35 for adjustment for balancing the introduction speed of the atmospheric pressure with the introduction speed of the negative pressure is provided on the atmospheric pressure introduction port side of the switching valve 31 having such a configuration. There is.

Next, the switching means 3 having such a structure.
The control means 5 for controlling the switching operation of is composed of a microcomputer or the like formed on the basis of arithmetic means such as a microprocessor unit (MPU), detects vibration from a vibrating body such as an engine, and Depending on the vibration
The switching operation of the switching means 3 is controlled.

Next, the operation mode and the like of the present embodiment having such a configuration will be described. That is, the vibration from the vibrating body side is propagated to the insulator 2 made of a rubber material or the like via the upper connecting member 6 as shown in FIG. Along with this, the insulator 2 vibrates or deforms to absorb or block most of the input vibration. Therefore, most of the vibrations are blocked at the insulator 2, but some of the vibrations are not blocked at the insulator 2 but blocked at the next vibration isolation mechanism section 1. Become. Next, a specific operation of the vibration isolation mechanism 1 will be described. First, for idling vibration, by operating the switching means 3,
Negative pressure or atmospheric pressure is alternately introduced into the equilibrium chamber 13 provided in the main chamber 12 at a specific frequency. That is, the pressure (volume) in the equilibrium chamber 13 is changed by operating the switching means 3 at a specific frequency, whereby the insulator 2
The hydraulic pressure fluctuation in the main chamber 12 caused by the idling vibration input via the is absorbed. As a result, the dynamic spring constant of the spring system formed by the insulator 2 and the anti-vibration mechanism section 1 is reduced.

Particularly, in this case, in the case of the present embodiment, the main chamber 12 is provided with the communication passage 1 having a predetermined volume.
A second diaphragm 122 that is connected via 21 and that operates according to the fluctuation of the liquid pressure of the liquid in the main chamber 12.
Is provided, the second diaphragm 122 operates in accordance with the operation of the equilibrium chamber 13. At this time, in the present embodiment, the second diaphragm 122 and the main chamber 1 are
The liquid in the communication passage 121 connecting between the two and the two resonates with the volume change in the equilibrium chamber 13. As a result, the generated force (vibration energy) formed in the entire antivibration mechanism section 1 has a sine wave shape with a symmetrical waveform as shown in FIG. 3, for example. As a result, the idling vibration is accurately absorbed and blocked. Further, the generation of high-frequency component vibration that may occur in connection with the cutoff of the idling vibration is also suppressed.

For the engine shake, which has a lower frequency than the idling vibration, the liquid is allowed to flow in the orifice 15 connecting the main chamber 12 and the auxiliary chamber 16. By doing so, the engine shake is absorbed and cut off. That is, the vibration related to this engine shake is about 10H.
Since it has a frequency around z, it is difficult to cut off the vibration by lowering the dynamic spring constant. Therefore, in the present embodiment,
As shown in FIG. 1, a constant negative pressure is continuously introduced into the equilibrium chamber 13 forming the anti-vibration mechanism portion 1, and the first diaphragm forming the equilibrium chamber 13 is pulled down to lower the equilibrium chamber. Bring volume of 13 to zero. This prevents the volume of the equilibrium chamber 13 from changing. When the vibration from the vibrating body is propagated to the insulator 2 in such a state, the lower surface portion of the insulator 2 vibrates in response to the vibration, and the liquid in the main chamber 12 is positively subsidized. It operates so as to flow to the chamber 16 side. As a result, the liquid in the main chamber 12 flows through the orifice 15 toward the sub chamber 16 side. A predetermined damping force is generated by viscous resistance accompanying the flow of the liquid, and the engine shake is suppressed (damped) by this damping force.

In particular, in shutting off the engine shake, as shown in FIG. 2, in the one in which the second diaphragm 122 and the first diaphragm 11 are sucked at the same time so as not to operate, a negative pressure is applied to the equilibrium chamber 13. Is continuously introduced, the volume of the equilibrium chamber 13 becomes zero and the second diaphragm 122
The volume of the air chamber 125 formed in the upper part of the is also zero. As a result, when the vibration caused by the engine shake is propagated to the liquid in the main chamber 12 via the insulator 2, the liquid in the main chamber 12 is efficiently compressed and the sub chamber via the orifice 15 is generated. It will be sent to the 16 side. That is, the liquid in the main chamber 12 flows in the orifice 15. as a result,
A high damping characteristic is obtained by the flow action of the liquid in the orifice 15. Due to the action of this high damping characteristic, the vibration related to the engine shake is suppressed. The same applies to the case where the rigid partition wall 19 is provided below the second diaphragm 122 as shown in FIG. That is, the vibration (displacement) of the second diaphragm 122 that accompanies the vibration of the insulator 2 is regulated by the rigid partition wall 19, whereby the hydraulic pressure in the main chamber 12 rises and the main chamber 12 increases. Since the liquid in 12 is sent out to the sub chamber 16 side through the orifice 15, a high damping characteristic is obtained by the flow action of this liquid.

On the other hand, with respect to high frequency vibration of about 100 Hz to 600 Hz, which causes a muffled noise, which is a problem during running of the vehicle, the switching means 3 is operated,
The equilibrium chamber 13 is opened to the atmosphere. As a result, atmospheric pressure is introduced into the equilibrium chamber 13, and the first diaphragm 11 forming the main equilibrium chamber 13 is allowed to freely operate (vibrate). As a result, the liquid in the main chamber 12 flows relatively freely in the main chamber 12 with respect to the vibration input from the insulator 2 side. As a result, the dynamic spring constant of the spring system formed by the entire vibration damping device can be suppressed low.
Therefore, the effect of blocking vibrations in the high frequency range is enhanced.

[0023]

According to the present invention, the upper connecting member attached to the vibrating body, the lower connecting member attached to the member on the vehicle body side, and the vibrating body located between the upper connecting member and the lower connecting member. And an anti-vibration mechanism section that is provided in series with the insulator and that is formed in a liquid chamber or the like in which a liquid that is an incompressible fluid is sealed. Regarding a liquid-filled type vibration damping device, the vibration damping mechanism is configured such that a chamber wall is formed in a part of an insulator and a liquid is sealed in a main chamber and an orifice is provided in the main chamber. A sub-chamber connected to the main chamber and separated from the main chamber by a partition plate, an air chamber provided below the sub-chamber via a third diaphragm, and the main chamber described above. Under the room Between the main chamber and the sub chamber, the equilibrium chamber being formed so that either one of the atmospheric pressure and the negative pressure is introduced. Which is provided between
The liquid is formed so that the liquid in the main chamber is introduced through a communication passage having a predetermined volume, and is partitioned and formed through the second diaphragm, and the volume thereof is variable. And a third liquid chamber, and at least one of negative pressure and atmospheric pressure is continuously or synchronized with the engine vibration in the equilibrium chamber having such a configuration. Provided with a switching means for performing a switching operation so as to be introduced alternately in the state of
Since the control means for controlling the switching operation of the switching means is provided, the volume change in the equilibrium chamber is caused based on the operation of the switching means by the control action of the control means. , Thereby controlling the fluctuation of hydraulic pressure in the main chamber for various vibration inputs,
Finally, it has become possible to reduce the dynamic spring constant of the liquid-filled type vibration damping device and to form high damping characteristics in the low frequency range. As a result, various vibrations including idling vibration can be blocked.

Particularly, in the present invention, the liquid in the main chamber is formed between the main chamber and the sub chamber so as to be introduced through the communication passage having a predetermined volume, and the second chamber is formed. Since the third liquid chamber, which is partitioned and formed through the diaphragm and whose volume can be changed, is provided, the equilibrium chamber is operated in a predetermined cycle against the idling vibration ( It is possible to form a symmetrical waveform of the changing state of the vibrating force applied to the liquid in the main chamber when the negative pressure is introduced and the atmospheric pressure is introduced. It was As a result, the idling vibration can be accurately cut off.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the overall structure of a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing the overall structure of a second embodiment of the present invention.

FIG. 3 is a diagram showing a change state of an exciting force caused by the operation of the equilibrium chamber during idling vibration damping.

FIG. 4 is a diagram showing a change state of a vibrating force at the time of damping idling vibration in a conventional one.

FIG. 5 is a vertical cross-sectional view showing the overall configuration of a conventional example.

[Explanation of symbols]

1 Vibration isolation mechanism 11 First diaphragm (first diaphragm) 12 Main room 121 communication passage 122 Second Diaphragm (Second Diaphragm) 123 Fine passage 124 Third liquid chamber (third liquid chamber) 125 air chamber 126 small rooms 13 Equilibrium chamber 14 partition boards 15 Orifice 16 Sub-room 17 Third Diaphragm (Third Diaphragm) 18 air chamber 19 Rigid partition (partition) 191 opening 2 insulators 3 switching means 31 Switching valve 32 solenoid 35 Throttle valve 5 Control means 6 Upper connecting member 9 Lower connection member

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-87178 (JP, A) JP-A-5-79529 (JP, A) JP-A-5-44769 (JP, A) JP-A-5- 18433 (JP, A) JP-A-10-61715 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16F 13/26

Claims (3)

(57) [Claims] 1. An upper connecting member attached to a vibrating body, a lower connecting member attached to a member or the like on a vehicle body, and absorbing and blocking vibrations from the vibrating body between the upper connecting member and the lower connecting member. And a vibration-damping mechanism portion that is provided in series with the insulator and that is formed of a liquid chamber or the like in which a liquid that is an incompressible fluid is sealed. In the device, the vibration isolating mechanism portion is connected to the main chamber in which the chamber wall is formed by a part of the insulator and in which liquid is sealed, and the main chamber via an orifice, and A sub chamber separated from the main chamber by a partition plate, an air chamber provided below the sub chamber via a third diaphragm, and a first chamber in the main chamber. Diaphragm Between the main chamber and the sub chamber, and an equilibrium chamber formed so that either one of the atmospheric pressure and the negative pressure is introduced. It is formed so that the liquid in the main chamber is introduced through the communication passage having a predetermined volume, and is partitioned and formed through the second diaphragm so that the volume can be changed. And a third liquid chamber that is formed, and either the negative pressure or the atmospheric pressure is continuously supplied to the equilibrium chamber having such a structure, or the engine vibration is generated. A liquid-filled type vibration damping device, characterized in that switching means for performing switching operation is provided so as to be alternately introduced in a state of being synchronized with, and control means for controlling the switching operation of the switching means is further provided. . 2. The liquid-filled type vibration damping device according to claim 1, wherein a surface of the second diaphragm provided at the vibration damping mechanism portion opposite to a side facing the third liquid chamber. A liquid-filled type vibration damping device, wherein the side faces the sub chamber through a partition wall having a plurality of openings. 3. The liquid-filled type vibration damping device according to claim 1, wherein a surface of the second diaphragm forming the vibration damping mechanism is opposite to a surface facing the third liquid chamber. A liquid-filled type vibration damping device, characterized in that an air chamber connected to the equilibrium chamber via a fine passage is provided.